<script>
export default {
    name: "TodoFooter",
    props:{
        taskList:{
            type:Array
        }
    },
    methods:{
        upIsAll(e){
            this.$emit("update:taskList",this.taskList.map(item=>{
                item.isChecked = e.target.checked;
                return item;
            }))
        },
        // 清除所有选中的任务数据
        clearCheckedTask(){
            // console.log("clearCheckedTask");
            this.$emit("update:taskList",this.taskList.filter(v=>!v.isChecked));
        }
    },
    computed:{
        overTaskNum(){
            return this.taskList.reduce(function(sum,item){
                if(item.isChecked) sum++;
                return sum;
            },0)
        },
        isAll(){
            return this.taskList.length>0 && this.taskList.length === this.overTaskNum;
        }
    }
}
</script>

<template>
    <div class="todo-footer">
        <label>
            <input @change="upIsAll" :checked="isAll" type="checkbox"/>
        </label>
        <span>已完成{{overTaskNum}} / 全部{{taskList.length}}</span>
        <button @click="clearCheckedTask" v-show="overTaskNum>0" class="btn btn-danger">清除已选中任务</button>
    </div>
</template>

<style scoped>
/*footer*/
.todo-footer {
    height: 40px;
    line-height: 40px;
    padding-left: 6px;
    margin-top: 5px;
}

.todo-footer label {
    display: inline-block;
    margin-right: 20px;
    cursor: pointer;
}

.todo-footer label input {
    position: relative;
    top: -1px;
    vertical-align: middle;
    margin-right: 5px;
}

.todo-footer button {
    float: right;
    margin-top: 5px;
}
</style>